275 research outputs found
Transforming High School Counseling: Counselors\u27 Roles, Practices, and Expectations for Students\u27 Success
This study examined the current roles and practices of American high school counselors in relation to the ASCA National Model. Expectations for student success by high school counselors were also examined and compared to those of teachers\u27 and school administrators\u27. A nationally representative sample of 852 lead counselors from 944 high schools was surveyed as part of the High School Longitudinal Study: 2009-2012. Findings are examined in the light of the National Model and advocated practices
Stochastic particle advection velocimetry (SPAV): theory, simulations, and proof-of-concept experiments
Particle tracking velocimetry (PTV) is widely used to measure time-resolved,
three-dimensional velocity and pressure fields in fluid dynamics research.
Inaccurate localization and tracking of particles is a key source of error in
PTV, especially for single camera defocusing, plenoptic imaging, and digital
in-line holography (DIH) sensors. To address this issue, we developed
stochastic particle advection velocimetry (SPAV): a statistical data loss that
improves the accuracy of PTV. SPAV is based on an explicit particle advection
model that predicts particle positions over time as a function of the estimated
velocity field. The model can account for non-ideal effects like drag on
inertial particles. A statistical data loss that compares the tracked and
advected particle positions, accounting for arbitrary localization and tracking
uncertainties, is derived and approximated. We implement our approach using a
physics-informed neural network, which simultaneously minimizes the SPAV data
loss, a Navier-Stokes physics loss, and a wall boundary loss, where
appropriate. Results are reported for simulated and experimental DIH-PTV
measurements of laminar and turbulent flows. Our statistical approach
significantly improves the accuracy of PTV reconstructions compared to a
conventional data loss, resulting in an average reduction of error close to
50%. Furthermore, our framework can be readily adapted to work with other data
assimilation techniques like state observer, Kalman filter, and
adjoint-variational methods
Neuronal Circuitry Mechanisms Regulating Adult Mammalian Neurogenesis
The adult mammalian brain is a dynamic structure, capable of remodeling in response to various physiological and pathological stimuli. One dramatic example of brain plasticity is the birth and subsequent integration of newborn neurons into the existing circuitry. This process, termed adult neurogenesis, recapitulates neural developmental events in two specialized adult brain regions: the lateral ventricles of the forebrain. Recent studies have begun to delineate how the existing neuronal circuits influence the dynamic process of adult neurogenesis, from activation of quiescent neural stem cells (NSCs) to the integration and survival of newborn neurons. Here, we review recent progress toward understanding the circuit-based regulation of adult neurogenesis in the hippocampus and olfactory bulb
Incorporating basic calibrations in existing machine-learned turbulence modeling
This work aims to incorporate basic calibrations of Reynolds-averaged
Navier-Stokes (RANS) models as part of machine learning (ML) frameworks. The ML
frameworks considered are tensor-basis neural network (TBNN), physics-informed
machine learning (PIML), and field inversion & machine learning (FIML) in J.
Fluid Mech., 2016, 807, 155-166, Phys. Rev. Fluids, 2017, 2(3), 034603 and J.
Comp. Phys., 2016, 305, 758-774, and the baseline RANS models are the
one-equation Spalart-Allmaras model, the two-equation - model, and
the seven-equation Reynolds stress transport models. ML frameworks are trained
against plane channel flow and shear-layer flow data. We compare the ML
frameworks and study whether the machine-learned augmentations are detrimental
outside the training set. The findings are summarized as follows. The
augmentations due to TBNN are detrimental. PIML leads to augmentations that are
beneficial inside the training dataset but detrimental outside it. These
results are not affected by the baseline RANS model. FIML's augmentations to
the two eddy viscosity models, where an inner-layer treatment already exists,
are largely neutral. Its augmentation to the seven-equation model, where an
inner-layer treatment does not exist, improves the mean flow prediction in a
channel. Furthermore, these FIML augmentations are mostly non-detrimental
outside the training dataset. In addition to reporting these results, the paper
offers physical explanations of the results. Last, we note that the conclusions
drawn here are confined to the ML frameworks and the flows considered in this
study. More detailed comparative studies and validation & verification studies
are needed to account for developments in recent years
The chemistry and structure of calcium (alumina) silicate hydrate: A study by XANES, ptychographic imaging, and wide- and small-angle scattering
Mott-Kondo Insulator Behavior in the Iron Oxychalcogenides
We perform a combined experimental-theoretical study of the
Fe-oxychalcogenides (FeO\emph{Ch}) series
LaOFeO\emph{M} (\emph{M}=S, Se), which is the latest
among the Fe-based materials with the potential \ to show unconventional
high-T superconductivity (HTSC). A combination of incoherent Hubbard
features in X-ray absorption (XAS) and resonant inelastic X-ray scattering
(RIXS) spectra, as well as resitivity data, reveal that the parent
FeO\emph{Ch} are correlation-driven insulators. To uncover microscopics
underlying these findings, we perform local density
approximation-plus-dynamical mean field theory (LDA+DMFT) calculations that
unravel a Mott-Kondo insulating state. Based upon good agreement between theory
and a range of data, we propose that FeO\emph{Ch} may constitute a new, ideal
testing ground to explore HTSC arising from a strange metal proximate to a
novel selective-Mott quantum criticality
KRASQ61H preferentially signals through MAPK in a RAF dimer-dependent manner in non-small cell lung cancer
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